New Study Shows Cannabis Effects on Driving Skills

WASHINGTON--March 1, 2013: New research appearing online
today in
Clinical Chemistry
, the journal of AACC, shows that cannabis can be detected in the blood of
daily smokers for a month after last intake. The scientific data in this
paper by Bergamaschi et al. can provide real help in the public safety need
for a drugged driving policy that reduces the number of drugged driving
accidents on the road.

Cannabis is second only to alcohol for causing impaired driving and
motor vehicle accidents. In 2009, 12.8% of young adults reported driving
under the influence of illicit drugs and in the 2007 National Roadside
Survey, more drivers tested positive for drugs than for alcohol. These
cannabis smokers had a 10-fold increase in car crash injury compared with
infrequent or nonusers after adjustment for blood alcohol
concentration.

In this paper, 30 male chronic daily cannabis smokers resided on a
secure research unit for up to 33 days, with daily blood collection.
Twenty-seven of 30 participants were THC-positive on admission, with a
median (range) concentration of 1.4 mcg/L (0.3--6.3). THC
decreased gradually with only 1 of 11 participants negative at 26 days; 2
of 5 remained THC-positive (0.3 mcg/L) for 30 days.

These results demonstrate, for the first time, that cannabinoids can be
detected in blood of chronic daily cannabis smokers during a month of
sustained abstinence. This is consistent with the time course of persisting
neurocognitive impairment reported in recent studies and suggests that
establishment of 'per se' THC legislation might achieve a reduction in
motor vehicle injuries and deaths. This same type of 'per se' alcohol
legislation improved prosecution of drunk drivers and dramatically reduced
alcohol-related deaths.

"These data have never been obtained previously due to the cost and
difficulty of studying chronic daily cannabis smoking over an extended
period," said Dr. Marylin Huestis of the
National Institutes of Health and author on the paper. "These data add
critical information to the debate about the toxicity of chronic daily
cannabis smoking."

About AACC--
The American Association for Clinical Chemistry, AACC, brings together
the global laboratory medicine community in the pursuit of improving health
and healthcare through laboratory medicine. With more than 8,500 members
including MDs, PhDs, research scientists, and others involved in developing
tests and directing laboratory operations, AACC advances scientific
collaboration, knowledge, expertise and innovation through its many
programs, publications and initiatives.

Clinical Chemistry is the leading international journal of
clinical laboratory science, providing 2,000 pages per year of
peer-reviewed papers that advance the science of the field. With an impact
factor of 7.9, Clinical Chemistry covers everything from molecular
diagnostics to laboratory management.